1. The Field of the Invention
The invention concerns a device for humidifying the useful space of a climatic test cabinet, especially a gassing incubator.
2. Present State of the Art
Various types of humidifying devices are used to humidify the air in the useful space of climatic test cabinets or gassing incubators. According to one type, water from a water supply outside the useful space is vaporized and the aerosol is fed into the useful space. Another way of humidifying the air in the useful space is by arranging a water container directly in the useful space and evaporating the water therein. Normally for this purpose a separately removable water trough is arranged on the floor of the useful space and heated with a suitable heating device. The heating element can be arranged directly in the water bath or in the immediate vicinity of the water bath. Alternatively, the useful space is equipped with a trough-shaped bottom area.
For example, a humidifying or steam sterilization device according to the last-mentioned principle is known from DE-AS 10 27 368. This patent describes a sterilization cabinet having a useful space with a floor area in the form of a trough which is filled with water to be evaporated. The water is connected with an external water supply container via a feed and drain system. Toward the door of the sterilization cabinet, the trough is bordered by a wall-like vertical plate.
A gassing incubator is also known from DE 38 15 528 which is also equipped with a water-filled trough on the floor of the useful space or with a floor area of the useful space in the form of a trough, which is intended to humidify the useful space. If an inserted rectangular trough is used, then it lies flat on the floor of the useful space and is bordered on all four sides by vertical side walls which prevent the water flowing out.
In the case when the floor of the useful space is shaped like a trough, a cross-strip is arranged in the lower part of the opening of the gassing incubator's useful space. This design makes it quite difficult to clean the water container in the floor area of the useful space, especially in the front area pointing toward the opening of the useful space. This is because the front cross-strip makes the area lying directly behind it only poorly accessible for inspection and for introducing cleaning materials, such as, for example cleaning cloths.
When a separate removable trough is used with a level floor and vertical side walls all around it, there is the further disadvantage that condensation forms outside the trough. Precisely in the front area of the useful space near the opening, the water bath which projects into this area encourages the humidity of the outside air entering at the opening of the useful space to condense outside on the side walls of the trough. The so-called humidity recovery time, which is the time required after the gassing incubator is opened until the humidity values have restabilized, is also substantially longer for a humidifying device with a removable trough. This is because such designs provide relatively poor heat transfer from the heating device to the water bath compared to a useful space with a built-in trough-shaped floor area.